Not too much of a good thing with Novacq

August 3rd, 2020

Water management strategies are continually evolving in prawn farming as a result of strict environmental regulations, as well as diseases outbreaks. Green water culture systems are widely used worldwide and are based on the growth of photoautotrophic organisms. Alternatively, boosting heterotrophic bacteria in the medium is becoming a common practice during the nursery phase. This technique helps to control ammonia peaks especially in the first days of culture and enables minimal water exchange.

Beyond the control of water quality, these microorganisms can also provide a source of food for prawns. The nutritive benefits of microbial biomass products have been characterised through feeding the commercially available, microbial biomass feed additive, Novacq™ in clear and green water systems. However, the combined effect of rearing prawns in culture conditions dominated by heterotrophic organisms and providing additional microbial biomass in feed has not been evaluated. Can microbial biomass be too much of a good thing?

Our three experiments aimed to provide initial insights on:

  • the effects of Novacq™ in different culture conditions
    • dominated by heterotrophic organisms
    • dominated by photoautotrophic organisms
  • the effect of nutritional history on performance in a clear water feeding trial.

In all three culture conditions investigated, dominated by heterotrophic or photoautotrophic organisms, and clear water, NovacqTM supplementation supported shrimp biomass gain and survival. Our findings contribute to the growing literature on the benefits of feeding NovacqTM to prawns, including improved survival, growth, feed intake and nutrient retention efficiency.

Collectively, the present findings strongly point towards the positive impact of continually feeding NovacqTM-based feeds throughout the culture cycle to maximise production performance. Now, coming back to the question “Can microbial biomass be too much of a good thing?” No(vacqTM)!

For more information, read our Global Aquaculture Alliance article.

Contacts:

Dr Artur Rombenso – CSIRO Livestock & Aquaculture, Research Scientist, CSIRO

Dr Matthew Briggs – Ridley Aquafeeds, Technical Project Manager